This invention relates to a netting system for fruit trees and in particular to the use of a net system in an established orchard of young or mature trees. The system is particularly adaptable to an orchard where the irregularity of terrain or lack of symmetry in the size and shape of trees makes a system as described in our U.S. Pat. No. 4,901,513 difficult or impossible to effectively install. Other embodiments can be used for individual trees or for trees organized in a uniform arrangement in an orchard.
It has been found that the system described in our referenced patent is more suitable for a uniform orchard of young or medium size trees and is particularly adapted to a new orchard where a center netting support pole is initially useful for assisting in the support of a young tree before the netting collection system is needed and installed. For fully mature trees having a dense foliage, such as a macadamia nut tree, it is difficult to install poles through the branches in line with the trunk and erect a netting around the tree.
The use of a netting system for fruit or nut trees is advantageous to gather falling fruit or nuts above ground to prevent spoilage and to facilitate periodic collection. For certain types of trees, such as the macadamia, where the nuts fall all during the year, the netting system substantially reduces the labor costs involved in repeated gathering. Because the rough, volcanic rock terrain frequently encountered in macadamia nut orchards often prevents expedient, mechanical collection, gathering fallen nuts must be accomplished manually with many nuts lost in lava rock soils. Additionally, macadamia nut trees are often planted on volcanic slopes where an interconnected orchard system has installation problems, and an individual netting system for each tree is sometimes preferred.
Where orchards include tens or hundreds of thousands of trees, the netting system must include components that are inexpensive and easy to assemble and erect to minimize capital expenses and labor costs involved in installing a system throughout a large orchard.
In a macadamia nut orchard having mature trees, the netting system must be erected around trees that may be forty feet high, with fruit bearing branches spanning a twenty five foot across collection area. Given the exposed terrain of many fruit and nut trees, a netting system that can withstand buffeting winds and periodically wet conditions is required.
It has been found that the use of semi-rigid supports is preferred over rigid supports to minimize damage from weather conditions. Common plastic tube ordinarily used as water pipe, is both durable and weather resistant. The plastic conduit is inexpensive, uniform, and readily available. Although plastic conduit for use long support poles lacks certain characteristics of structural integrity inherent in such natural semi-rigid poles as bamboo, the flexibility of the conduit pole can be controlled by the system design. Additionally, heavy, semi-rigid wire, preferably coated with a plastic, weather-proof coating is useable. The wire should have characteristics similar to common coat-hanger wire with equal or greater thickness and stiffness. While uncoated aluminum wire can be used, coated wire minimizes abrasion wear on the interconnected net.
The use of structural struts to assist in supporting a collection netting is not new. In the early U.S. Pat. No. 1,256,890 of Flynn, issued Feb. 19, 1918, entitled, Fruit Gatherer, struts connected at one end to a belt around the base of a tree and at the other end to the perimeter of the net served to support a net cinched around the trunk by a collar above the anchoring belt for the struts. Although this system is suitable for smaller trees where rigid struts are used, the system is not suitable for large trees where the length of the strut would allow unacceptable bending unless fabricated from a size that becomes uneconomical. Similarly, a system using metal struts disclosed in the Swiss Patent No. 32,843 of Daniken, issued Mar. 7, 1905 uses the struts to support the net and is practical only for smaller trees. In U.S. Pat. No. 57,766 of Rauschert, issued Sept. 4, 1866 and, Austria Patent No. 48,519 of Reimertshofer et al, issued Jan. 1, 1911 struts are used that abut the tree and connect to the perimeter of the net which are subject to excess bending as the collection area is increased.
In Swiss Patent No. 159,089 of Haase, issued Dec. 31, 1932 a netting system is disclosed in which contoured struts appear to be anchored to a belt and in part supported by the overlying net to which the strut is tied along the length of the strut. However, except for the tree branches proximate the net there is no means to stabilize the conical net during winds other than the overall rigidity of the assembly.
In U.S. Pat. No. 816,186 of Roberts, stakes are driven into the ground in a perimeter around the tree displaced from the trunk. The distal ends of the stakes are angled outwardly and connect to the perimeter of a net supported above the stakes with the net cinched around the trunk of the tree. While the stakes provide stable supports for a tree, they must be of limited length to remain rigid and as installed, limit access near the trunk of the tree.
These deficiencies in prior art systems inspired the development of systems that are adapted to large trees, yet remain inexpensive and easy to erect. While the problem of devising an efficient fruit gathering net may appear trivial, when applied to an orchard having thousands of trees, selection of materials and ease of assembly of structures is critical to viable implementation.